<html>
<head>
    <meta name='viewport' content='width=device-width,initial-scale=1'>
</head>
<script>
    let uploaded = 0;
    let buf = new Uint8Array(1024 * 50);
    let start = Date.now();
    var rs = new ReadableStream({
       pull(ctrl) {
          uploaded += buf.byteLength;
          crypto.getRandomValues(buf);
          ctrl.enqueue(buf);
          if ((start + 1000) < Date.now()) { ctrl.close() };
       }
   });
    function test(url) {
          fetch(url, {
                method: 'POST',
                body: rs,
                duplex: 'half'
          }).then(r => JSON.stringify( r.json()) ).then(console.log).catch();
          console.log('execute end');
    }
     function testError(url) {
          fetch(url, {
              method: 'POST',
              body: rs,
              duplex: 'half'
          }).then(r => JSON.stringify(r.json()) ).then(console.log);
     }
</script>
<body>
<div onclick='test()'>test post chunked http body.</div>
test()
</body>
</html>